1. Field of the Invention
This invention relates to new and useful compounds, 5-alkoxy-picolinic acids, the pharmaceutically acceptable inorganic salts thereof and the organic esters thereof and to a process for preparing the same.
2. Description of the Prior Art
It has been known that hypertension often induces apoplexy, heart trouble, etc., which necessitates extensive research for new and useful anti-hypertensives.
Fusaric acid (5-n-butylpicolinic acid) is known to be useful as an antihypertensive agent as disclosed in Jap. J. Pharmocol., Vol. 25, 188 (1975), however, fusaric acid has a butyl group at the 5-position of the picolinic acid moiety and has a low LD.sub.50 value. As a result, an improved antihypertensive agent is desired.
U.S. Patent Application Ser. No. 700,340, filed June 28, 1976, now U.S. Pat. No. 4,083,850 discloses that 3-substituted-2(1H)-pyridone-6-carboxylic acid can be used as an antihypertensive agent but, the antihypertensive activity (i.e., maximum depression in blood pressure) thereof is poor and an improvement is desired.